Deployable truss beam with orthogonally-hinged folding diagonals

ABSTRACT

A deployable single truss with folding or removable chordal members and diagonals and orthogonal hinge joints for continuous and synchronous retraction and extension, in straight and curved configurations. A deployable dual rectangular truss comprised of two single trusses mated along two common chords. A deployable diamond truss comprised of two single trusses mated along one common chord. An end frame to close off or mount one of more ends of the deployable trusses. A primary orthogonal hinge joint to connect the chordal members and diagonals of the deployable trusses along a primary chord. A secondary orthogonal hinge joint to connect the chordal members and diagonals of the deployable trusses along a secondary chord.

BACKGROUND OF THE INVENTION

[0001] This invention relates generally to deployable truss beams, and more particularly to the apparatus and manner in which a three-dimensional, tetrahedron-based truss of square or rectangular section can be expanded and retracted in a continuous, stable, synchronous fashion in a variety of combinations and configurations to form a load-carrying beam or mast. Four longitudinal truss chords are formed by primary and secondary chord members, which can be formed by hinged, rigid, or flexible members. Chord members are connected by framesets comprised of truss diagonal members. Continuous, stable and synchronous motion while extending and retracting the truss is achieved by the use of uniquely incorporated orthogonal hinge joint fittings connecting the framesets and the chord members. The orthogonal hinge joint axes become orthogonal to each other at full extension of the truss and remain parallel at all times.

[0002] There have been many attempts to design, for various operating environments, a practical compact folding or flexing truss structure which can transition easily between the retracted and the useful extended state while exhibiting favorable characteristics of size/volume ratio, kinematic stability, simplicity and reliability, structural efficiency and weight, complexity, auxiliary mechanism requirements, manufacturing costs, speed of operation, and operating cost. Relatively few designs have appeared in the marketplace. Notable high-profile, and high-flying, examples are deployable trusses used in space missions such as for solar array deployment on NASA's International Space Station. Undesirable features of existing deployable trusses include complexity, inability to move in a coordinated and synchronous manner, requirements for a dedicated deployer and auxiliary mechanisms, and high cost.

[0003] Thus, what is needed is a deployable truss that achieves synchronous coordinated motion of all members while extending or retracting, is stable and self-forming and requires no dedicated auxiliary mechanisms and structures, and yet remains low in weight, complexity, and cost.

SUMMARY OF THE INVENTION

[0004] This invention relates to the apparatus and manner in which a three-dimensional, tetrahedron-based truss of square or rectangular section can be expanded and retracted in a stable, synchronous fashion in a variety of combinations and configurations to form a load-carrying beam or mast. The basic single truss comprises four longitudinal truss chords which are formed by primary and secondary chord members. These chord members can be either compression or tension members. Compression chord members may be hinged so they fold during retraction of the truss, or rigid members that are affixed to the truss after extension. Tension chord members may be flexible or hinged. Chord members are connected by framesets comprised of truss diagonal members. Continuous, stable and synchronous motion while extending and retracting the truss is achieved by the use of uniquely incorporated orthogonal hinge joint fittings connecting the framesets and the chord members. The orthogonal hinge joint axes become orthogonal to each other at full extension of the truss and remain parallel at all times. When fully deployed, the basic single truss forms three planar trusses, of Warren pattern, integrally joined along two common chords, with an open face between two secondary chords.

[0005] In the basic form, the invention can be used as a beam or a mast in a wide variety of applications. As a beam, it can be supported or mounted at each end, or cantilever mounted. As a mast, it is base-mounted with guy cables as required. End bearing pads may be affixed to the ends of the chordal members and end struts to provide additional stability and strength when the truss is deployed.

[0006] In an alternative embodiment of the basic single configuration, additional diagonals are added between the two secondary chords for additional strength and stability.

[0007] Another alternative embodiment of the invention is a dual rectangular configuration, where two single section trusses are connected along two secondary chords, providing greater strength and stability. Advantages include the ability to withstand transverse load reversal and, as a mast, no requirement for guy cables. In a variation on this embodiment, the side diagonals are removed from the long side of the dual rectangular configuration to reduce cost and weight.

[0008] A further alternative embodiment is a dual diamond configuration, where two single section trusses are connected along one secondary chord, with additional cross ties or members providing greater strength and stability.

[0009] Another embodiment is a curved configuration of the basic single truss and the dual rectangular truss configurations, where the chordal members are varied in length and the joints contain an angular offset so that the longitudinal axis of the truss follows a prescribed curve.

[0010] Thus, the invention in its various embodiments possesses several favorable characteristics relative to those trusses cited above, including, but not limited to, (i) use of the new orthogonal hinge folding method to achieve synchronous, coordinated motion of all members during extension or retraction, (ii) greater stability, (iii) self formation, so that no dedicated auxiliary mechanisms or structures are required other than simple means to offset gravity and friction, if required, (iv) deployment along the truss longitudinal axis with a length extension ratio that can be, but does not have to be, more than 15 times the retracted length, (v) minimization of cost, weight, and complexity by the elimination of unnecessary truss members and use of alternative forms of truss chordal members, and (vi) adaptability to actuation methods that can vary from fully manual to fully automatic, depending on the application requirements. Applications for the invention include, but are not limited to, scaffolding, platforms and construction equipment, crane and equipment booms, towers and masts, vehicle frames, theater stage roofs and lighting equipment, stowable equipment mounts, shelters, space structures and space vehicle booms, and exhibition display frames.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 shows the general configuration of the basic single deployable truss beam in the retracted and extended (deployed) states and with principal components and features identified.

[0012]FIG. 2 shows the end views of single truss framesets in the extended and retracted states with frame and hinge axis layout geometry.

[0013]FIG. 3 shows the formation of a single truss framebay from two truss framesets and a primary and secondary chordal member, and the method of mounting a major and minor joint of the truss to an end frame.

[0014]FIG. 4 shows views of the orthogonal hinge joint fittings and hinge fitting geometry.

[0015]FIG. 5 shows the formation of a dual diamond truss configuration by mating two basic single-section trusses along a secondary chord, and adding interconnecting members.

[0016]FIG. 6 shows the formation of a dual rectangular truss configuration by mating two basic single-section trusses along two common secondary chords.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017]FIG. 1 shows the general configuration of a deployable single-section truss beam in the in the retracted and extended (deployed) states. Four longitudinal truss chords are formed by primary 1, and secondary 2 chordal members. As depicted in FIG. 1, the primary chordal members are compression structures and the secondary chordal members are tension structures, although the chordal members are not limited to this configuration. Compression chordal members may be rigid or hinged 1, while tension chordal members may be flexible, hinged or cables 2.

[0018] The primary chords 1 are laterally connected by base diagonal members 6. Each secondary chord 2 is laterally connected with the proximal primary chord by side diagonal members 3. When deployed, the structure is equivalent to three planar trusses of Warren pattern with two common chords.

[0019] Primary orthogonal hinge joints 4 connect the ends of the primary chordal members that form the primary chords and the respective side and base diagonal members. Secondary orthogonal hinge joints 7 connect the ends of the secondary chordal members that form the secondary chords and the respective side diagonal members.

[0020] One end of the truss is connected to a truss end frame 13 a at a primary orthogonal hinge and a secondary orthogonal hinge joint. For greater strength and stability, the truss may also be attached to the end frame at two additional points through the use of a primary strut 14 and a secondary strut 15. A second end frame 13 b may be connected to the opposite end of the truss, but is not required.

[0021]FIG. 2 shows the basic geometry of the diagonal members making up a truss frameset 5. A base diagonal member 6 connects at both ends to two side diagonal members 2 through two base joints 4 a, which will ultimately form two primary orthogonal hinge joints 4. In the preferred embodiment, the base diagonal member has a rotary joint 6 a somewhere along its length, not necessarily at its center. The opposite ends of the side diagonal members connect to other framesets and secondary chordal members through secondary orthogonal hinge joints 7. The orthogonal hinge axes become orthogonal (90 degrees) to each other at full extension, and remain parallel at all times.

[0022] The length between apexes of the frameset is the diagonal length “L” of the reference single truss having width “W.” The side diagonals are also length “L” with angle “a” calculated from the reference single truss geometry. The lines opposite angles “a” are of length 1.414(W), equal to the truss diagonal. The primary orthogonal hinges are at the corner apexes with their axes parallel to these lines. The secondary orthogonal hinges are at the end of each side diagonal with their axes parallel to the respective primary orthogonal hinge axes.

[0023]FIG. 3 shows how two framesets are connected together to form a truss frameset subassembly and, with the addition of chordal members, a truss framebay 8. A frameset subassembly is formed by connecting two mirror-image framesets at one of their respective base joints 4 a to form a major joint 4, and at the free ends of their opposing side diagonals to form a minor joint 7 a. A primary chordal member 1 is connected to the two free base joints on the framesets, and a second chordal member 2 is connected to the two free ends of the two side diagonals connected to the major joint, to form a framebay 8. Mirror-imaged framebays then are connected in sequence at their respective major and minor joints. In the preferred embodiment, the major joints are primary orthogonal hinge joints and the minor joints are secondary orthogonal hinge joints. As seen in FIG. 3, orthogonal hinge axes are always parallel and become orthogonal at full extension.

[0024] Through the use of the orthogonal hinge joints 4 & 7, the expansion and retraction kinematics are such that a driven rotation of any joint, e.g. a diagonal rotary joint, results in a predictable motion of all other joints including the chordal members if hinged, as, for example, in a conventional “scissor” linkage. Chordal members that are center-hinged move in a “z-fold” manner and at full retraction are parallel-nested.

[0025] When retracted, each frameset, having one rotary joint in the preferred embodiment, nests parallel to its mirror image, connected through one primary and one secondary orthogonal hinge joint, thus representing two layers of truss diagonals and one truss framebay 8 as seen in FIG. 4. These two layers also contain the associated folding hinged chordal members 1 and the flexible chordal members 2 in the preferred embodiment.

[0026] The primary and secondary orthogonal hinge joints are each assembled from male and female halves to form the primary structural joints of the extended truss as shown in FIGS. 3 and 4. The primary orthogonal hinge joints have hinge pin connections 9 for the primary chordal members 1. The secondary orthogonal hinge joints 7 in FIG. 3 have connecting pins for the secondary chordal members 2 shown in this embodiment.

[0027]FIG. 4 shows side views of the primary 4 and secondary 7 orthogonal hinge joints and indicates their basic geometry. The primary orthogonal hinge joint when retracted occupies “2P” (where “P” is the frame pitch) or the thickness of one bay, with the main hinge axis centered and located in the hinge lugs. Each half of the primary orthogonal hinge joint receives two diagonals (one side and one base), attached to the lugs (or equivalent part), as seen in FIG. 2. The diagonal mount angle is “a/2” degrees as seen in FIG. 2. The lugs also provide the hinge pin connections for the primary chordal members, with axis location determined from angle “b” and distance “P”, such that when extended (unfolded) the hinge pins are coplanar and lie on the chordal axis as shown in the “extended” view. The thickness available for the primary chordal members, if folded, is “P.”

[0028] The secondary orthogonal hinge joints receive and connect the side diagonals as seen in FIG. 2. The hinge axis is co-planar with the primary orthogonal hinge axis. The diagonal mount angle is “a/2” degrees as seen in FIG. 2. As with the primary orthogonal hinge joints, the chordal member connection pin axes 10 as shown in FIG. 3D are located by angle “b” so that when unfolded the three hinge pins are coplanar and lie on the chordal axis.

[0029] Kinematically, the truss requires a minimum of only one force or torque to cause continuous, synchronous motion (synchronous meaning all parts are kinematically coupled). Although hinged chordal members, when used, can lock passively (by springs or the equivalent), forces are required to cause unlocking and initial rotation of the “knee” joints 11 prior to retraction of the full assembly, as seen in FIG. 3D. For fully automatic or semi-automatic operation, this implies the need for actuators whose selection will be dependent on the specific requirements of a given truss application.

[0030]FIGS. 1 and 3 depict the preferred method for connecting the truss ends to end mount frames 13 a & 13 b such that the truss chords are perpendicular to the end mount frames at full deployment, and parallel to the end mount frames when retracted. This is achieved by hinging the primary and secondary orthogonal hinge joints to the end mount frames at diagonal corners as seen in FIG. 3A, and using short primary and secondary struts 14 & 15 as seen in FIG. 1 to connect the other two diagonal corners. In the preferred embodiment, the primary strut is similar to but about the half the length of the full-length primary chordal member, but the two halves of the strut are of unequal length in order to obtain the proper folding geometry. Alternatively, the primary strut can be non-folding by having one end slide in a track on the respective end frame approximately parallel to the truss section diagonal line, with locking provision at full extension. As shown in FIG. 3B, one primary orthogonal hinge joint half requires a vertical axis pivot fitting 18 to accommodate the required rotation as seen in FIG. 2. With reference to FIG. 3D, the open face of the truss can be fitted with diagonal members, including but not limited to telescoping or hinged diagonals, in an alternative embodiment (see two diagonal phantom lines 16 connecting the secondary orthogonal hinge joints 7). Another alternative embodiment relative to the truss chords is to manually install simple compression chordal members after the truss is unfolded. Use of compression chordal members for all four chords permits bi-directional beam moment loading, if needed. In a further embodiment, end bearing pads may be affixed to the ends of the chordal members and primary or secondary struts as appropriate, to provide additional stability and strength when the truss is deployed.

[0031] In a number of alternative embodiments, derivative trusses can be created by lateral connection of identical basic single trusses to form rectangular or diamond shapes.

[0032]FIG. 5 discloses a diamond-shaped truss comprised of two single trusses in which mirror images are joined at a common chord through the secondary orthogonal hinge joints. Additional cross or transverse members or ties are added as needed for the applied loading and stiffness. Two end mount frames may be connected at one corner to create a diamond end mount frame.

[0033]FIG. 6 discloses a dual rectangular truss configuration in which two single truss mirror images are joined along their two common secondary chords to create a rectangular section when extended. The secondary chordal members are eliminated, and the side diagonal members 3 become cross-bracing members. Thus, the two primary chords of the component single trusses become the four chords of the dual rectangular truss. Connection of the respective secondary orthogonal hinge joints is accomplished with clevis end hinge fittings 17 or equivalent, which connect the secondary orthogonal hinge joint hinge pins and permit the required rotation. Two end frames are hinged together through an axis that is collinear with the hinge fittings 17 which connect the secondary orthogonal hinge joints, and thus form a dual end frame. At full extension when the frames have rotated toward each other they are latched together to form the load interface (end) structure.

[0034] In an alternative embodiment of the dual rectangular truss, two adjoining side diagonal members 3 are removed from the dual rectangular truss frameset to create an open face. This configuration is designed to lower cost and weight.

[0035] The basic single truss and the dual rectangular truss, either in open-faced or closed-face configurations, can be curved along the truss longitudinal axis. If it is desired that the truss longitudinal axis be curved rather than straight, the primary orthogonal hinge joints can incorporate an in-plane castor angle 12, as seen in FIG. 3C, of a calculated magnitude “c” to create an angle between truss framebays, with the chordal member lengths adjusted to match.

[0036] For all embodiments, if gravity loading is not present or if the truss frames are supported by rollers or equivalent, a preferred method of deployment is application of an axial force at the end frame to both extend and retract. The chordal members, if hinged, are spring locked at full extension. To begin the retraction process, any hinged chordal members are unlocked and given an initial rotation as mentioned above. This is done either manually or by an actuation mechanism. The actuation components can be located on the chordal members or centrally located using pull cables.

[0037] For extension/retraction on a level or sloping surface, a preferred support method is the use of low-friction caster wheels attached to the primary orthogonal hinge joints to support the truss frames. When no support surface or floor is available, the truss can be supported by various simple cable/winch arrangements during extension and retraction. For long trusses, a vertical center hinge can be provided so that the two sections can be extended side-by-side until locked, then the end section rotated 180 degrees and locked.

[0038] Even though specific embodiments of this invention have been described, they are not to be taken as exhaustive. There are several variations that will be apparent to those skilled in the art, including multiple combinations of the basic single-section truss beyond the dual and curved configurations described herein. 

I claim:
 1. A deployable truss with proximal and distal ends, comprising: a. a plurality of framesets, each frameset having a base diagonal member and a first and second side diagonal members, said base and side diagonal members each having a first and second end, said first side diagonal member being connected at its first end adjacent to said first end of said base diagonal member at a first base joint, and the second side diagonal member being connected at its first end adjacent to said second end of said base diagonal member at a second base joint; b. a plurality of framebay subassemblies, each framebay subassembly comprising two of said framesets being connected at one of their respective first or second base joints at a first major joint, and by connection of one first or second side diagonal member of each frameset adjacent their respective second ends at a first minor joint; c. a plurality of framebays, each framebay comprising a framebay subassembly, a primary chord member connected at its ends adjacent to the other respective first or second base joints of the framebay subassembly at second and third major joints, and a secondary chord member connected at its ends adjacent to the second ends of the other respective side diagonal members of each framebay subassembly at second and third minor joints; d. an end frame connected to the framebay adjacent to one of said proximal and distal ends at one of the respective second or third major joints and one of said second or third minor joints of said framebay; e. a primary strut with two ends, connected at one end adjacent to said end frame and at the other end adjacent to the first major joint of the framebay adjacent to one of said proximal and distal ends; and f. a secondary strut with two ends, connected at one end adjacent to said end frame and at the other end adjacent to the first minor joint of the framebay adjacent to one of said proximal and distal ends.
 2. A deployable truss with proximal and distal ends as in claim 1, further comprising: a. a second end frame connected to the framebay adjacent to the other of said proximal and distal ends at one of the respective second or third major joints and one of said second or third minor joints of said framebay; b. an additional primary strut with two ends, connected at one end adjacent to said second end frame and at the other end adjacent to the first major joint of the framebay adjacent to one of said proximal and distal ends; and c. an additional secondary strut with two ends, connected at one end adjacent to said second end frame and at the other end adjacent to the first minor joint of the framebay adjacent to one of said proximal and distal ends.
 3. A deployable truss with proximal and distal ends as in claim 1, wherein each framebay further comprises two open-face diagonal members with two ends, each connected at one end adjacent to said first minor joint of the framebay and at the other ends adjacent to the respective second and third minor joints of the framebay.
 4. A deployable truss with proximal and distal ends, comprising: a. a plurality of framesets, each frameset having a base diagonal member and a first and second side diagonal members, said base and side diagonal members each having a first and second end, said first side diagonal member being connected at its first end adjacent to said first end of said base diagonal member at a first base joint, and the second side diagonal member being connected at its first end adjacent to said second end of said base diagonal member at a second base joint; b. a plurality of double frameset assemblies, comprising a pair of said framesets, the side diagonal members of one of said framesets being connected at their second ends adjacent to the seconds ends of the side diagonals of the other of said framesets at a first and second minor joint; c. a plurality of double framebay subassemblies, each double framebay subassembly comprising two of said double frameset assemblies being connected at two of their respective first or second base joints at a first and second major joint, and at one of their respective first or second minor joints; d. a plurality of double framebays, each double framebay comprising a double framebay subassembly, and two primary chord members connected at their ends adjacent to the other respective first or second base joints of the double framebay subassembly at third, fourth, fifth and sixth major joints; e. a dual end frame connected to the double framebay adjacent to one of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and one of said minor joints of said double framebay; and f. two primary struts with two ends, each connected at one end adjacent to said dual end frame and at the other end adjacent to the respective first or second major joints of the double framebay adjacent to one of said proximal and distal ends.
 5. A deployable truss with proximal and distal ends as in claim 4, further comprising: a. a second dual end frame connected to the double framebay adjacent to the other of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and one of said minor joints of said double framebay; and b. two additional primary struts with two ends, each connected at one end adjacent to said second dual end frame and at the other end adjacent to the respective first or second major joints of the double framebay adjacent to one of said proximal and distal ends.
 6. A deployable truss with proximal and distal ends, comprising: a. a plurality of rectangular framesets, each rectangular frameset having a first and second base diagonal member and a first and second side diagonal member, said base and side diagonal members each having a first and second end, said first base diagonal member being connected at its first end adjacent to said first end of said first side diagonal member at a first base joint, said first side diagonal member being further connected adjacent to its second end to the second end of said second side diagonal member at a first minor joint, and said second side diagonal member being further connected adjacent to its first end to the first end of said second base diagonal member at a second base joint; b. a plurality of rectangular framebay subassemblies, each rectangular framebay subassembly comprising two of said rectangular framesets being connected at their respective first or second base joints at a first and second major joint; c. a plurality of rectangular framebays, each rectangular framebay comprising a rectangular framebay subassembly, and two primary chord members connected at their ends adjacent to the second ends of the respective first and second base diagonal members of said rectangular framebay subassembly at third, fourth, fifth and sixth major joints; d. a dual end frame connected to the rectangular framebay adjacent to one of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and one of said minor joints of said rectangular framebay; and e. two primary struts with two ends, each connected at one end adjacent to said dual end frame and at the other end adjacent to the respective first or second major joints of the rectangular framebay adjacent to one of said proximal and distal end.
 7. A deployable truss with proximal and distal ends as in claim 6, further comprising: a. a second dual end frame connected to the rectangular framebay adjacent to the other of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and one of said minor joints of said rectangular framebay; and b. two additional primary struts with two ends, each connected at one end adjacent to said second dual end frame and at the other end adjacent to the respective first or second major joints of the rectangular framebay adjacent to one of said proximal and distal ends.
 8. A deployable truss with proximal and distal ends, comprising: a. a plurality of framesets, each frameset having a base diagonal member and a first and second side diagonal members, said base and side diagonal members each having a first and second end, said first side diagonal member being connected at its first end adjacent to said first end of said base diagonal member at a first base joint, and the second side diagonal member being connected at its first end adjacent to said second end of said base diagonal member at a second base joint; b. a plurality of diamond frameset assemblies, comprising a pair of said framesets, the first side diagonal member of one of said framesets being connected at its second end adjacent to the second end of the second side diagonal of the other of said framesets at a first minor joint; c. a plurality of diamond framebay subassemblies, each double framebay subassembly comprising two of said diamond frameset assemblies being connected at their respective first minor joints and at two of their respective first or second base joints at a first and second major joints; d. a plurality of diamond framebays, each diamond framebay comprising a diamond framebay subassembly, two primary chord members connected at their ends adjacent to the other respective first or second base joints of the diamond framebay subassembly at third, fourth, fifth and sixth major joints, two secondary chord members connected at their ends adjacent to the second ends of the respective second and first side diagonal members of said diamond framebay subassembly at second, third, fourth and fifth minor joints, a transverse member connected at both ends adjacent to two of said second, third, fourth or fifth minor joints, and a tie strut connected at both ends to two of said third, fourth, fifth or sixth major joints; e. a diamond end frame connected to the diamond framebay adjacent to one of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and two of the respective second, third, fourth or fifth minor joints of said diamond framebay; f. two primary struts with two ends, each connected at one end adjacent to said diamond end frame and at the other end adjacent to the respective first or second major joints of the diamond framebay adjacent to one of said proximal and distal ends; and g. one secondary strut with two ends, connected at one end adjacent to said diamond end frame and at the other end adjacent to the first minor joint of the diamond framebay adjacent to one of said proximal and distal ends.
 9. A deployable truss with proximal and distal ends as in claim 8, further comprising: a. a second diamond end frame connected to the diamond framebay adjacent to the other of said proximal and distal ends at two of the respective third, fourth, fifth or sixth major joints and two of the respective second, third, fourth or fifth minor joints of said diamond framebay; b. two additional primary struts with two ends, each connected at one end adjacent to said second diamond end frame and at the other end adjacent to the respective first or second major joints of said diamond framebay; and c. one additional secondary strut with two ends, connected at one end adjacent to said second diamond end frame and at the other end adjacent to the first minor joint of said diamond framebay.
 10. A deployable truss with proximal and distal ends as in claims 1, 4, 6, or 8, wherein said primary chord members further comprise a centrally-hinged folding member that locks at full extension of the truss, a fixed rigid member connected after full extension of the truss, or a structure adapted to provide compressive strength.
 11. A deployable truss with proximal and distal ends as in claims 1 or 8, wherein said secondary chord members further comprise a centrally-hinged folding member that locks at full extension of the truss, a fixed rigid member connected after full extension of the truss, or a structure adapted to provide compressive strength.
 12. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein said primary chord members further comprise a flexible member, a centrally-hinged folding member, a cable, or a structure adapted to provide tensile strength.
 13. A deployable truss with proximal and distal ends as in claims 1 or 8, wherein said secondary chord members further comprise a flexible member, a centrally-hinged folding member, a cable, or a structure adapted to provide tensile strength.
 14. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein said base diagonal members are adapted to be selectively rotated relative to their connections or are rotatably connected to said first and second major joints.
 15. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein said base diagonal members comprise two rigid portions rotatably connected.
 16. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein at least one of said major joints further comprises a primary orthogonal hinge joint.
 17. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein at least one of said minor joints further comprises a secondary orthogonal hinge joint.
 18. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, wherein respective framesets are adapted to collapse and expand in a coordinated, synchronous manner.
 19. A deployable truss with proximal and distal ends as in claims 1, 4, 6 or 8, further comprising a plurality of end bearing pads affixed to the ends of each chord member.
 20. A deployable truss with proximal and distal ends as in claims 1, 2, or 4-9, wherein said primary struts comprise two rigid members hingedly connected, or a single rigid member connected to a track sliding mechanism on the respective end frame.
 21. A deployable truss with proximal and distal ends as in claims 1, 2, 8 or 9, wherein said secondary struts comprise two rigid members hingedly connected, or a single rigid member connected to a track sliding mechanism on the respective end frame.
 22. A deployable truss with proximal and distal ends as in claims 1, 2, or 4-9, wherein the connection between a major joint and the respective end frame comprises a two-axis pivot fitting that permits rotational movement of the fitting during deployment of the truss.
 23. A deployable truss with proximal and distal ends as in claims 1, 3, or 6, wherein said chordal members are varied in length, and said major and minor joints contain an angular offset, so that the longitudinal axis of the truss follows a prescribed curve.
 24. A primary orthogonal hinge joint, comprising: a. a female half with two ends, one end comprising two parallel lugs with a sequence of matching holes in each lug for providing connecting points, and the other end comprising a pair of angled fittings for connecting tubular, beam or rod structures; and b. a male half with two ends, one end comprising two parallel lugs with a sequence of matching holes in each lug, designed to fit within the two parallel lugs of said female half and be hingedly connected to said female half by a main hinge pin inserted through a pair of matching holes in the lugs, and the other end comprising a pair of angled fittings for connecting tubular, beam or rod structures.
 25. A secondary orthogonal hinge joint, comprising: a. a female half with two ends, one end comprising two parallel lugs with a sequence of matching holes in each lug for providing connecting points, and the other end comprising a single angled fitting for connecting tubular, beam or rod structures; and b. a male half with two ends, one end comprising a single lug with a sequence of holes, designed to fit within the two parallel lugs of said female half and be hingedly connected to said female half by a main hinge pin inserted through a pair of matching holes in the lugs, and the other end comprising a single angled fitting for connecting tubular, beam or rod structures. 